Hydraulic valve adjusting means



July 10, 1945- E. w. KETTERING HYDRAULIC VALVE ADJUSTING MEANS Filed A rii 22, 1943 c fgy/zzz the valved part of a Patented 10,- 1945 asadon HYDRAULIC VALVE mmsrmo mans Eugene W. Kettering, Hinsdale, IIL, assignor to General Motors; Corporation, Detroit, Mloln, a

corporation of Delaware Application April 22, 1943, Serial No. 484,007

1 2 Claims. (01. 123-90) This invention relates to lash adjusters oi the hydraulic type as applied to the valves of internal combustion engines. The invention is particularly concerned with the bodily adjustment of the lash adjuster mechanism and with means to hold this mechanism in the adjusted position.

The invention is applied to a Diesel engine of the two-cycle type in'which each cylinder is provided with four outlet valves, each pair of valves being operated by a bridge extending between themjand this bridge in turn being actuated by a rocker arm operated from the usual rocker arm shaft. Each bridge has two hydraulic lash adjuster units mounted therein, each unit being in contact with the end of the valve stem. One unit is rigidly and permanently secured in the bridge, while the other unit is bodily adjustable, or adjustable as a whole in the bridge. The adjustable unit has a plurality of radial grooves or depressions on its under side and in these depressions there is adapted to seat the end of a spring mounted on the bridge. The spring holds the unit in adjusted position. A prong on the spring extends into a recess in the bridge to keep the spring from turning.

On'the drawing Figure 1 is a transverse sectional view through two-cycle, multi-cylinder Diesel engine, showing the application of the invention.

Figure 2 is an enlarged sectional detail View of the bridge and the Figure 3 is a detailed view of the spring, in perspective.

Referring to the drawing, 2 indicates a twocycle Diesel engine as a whole. The engine has a plurality of cylinder liners, one of which is indicated at I and in'each liner there operates a piston G. The engine has a cylinder head 8. secured to the cylinder liners by means of bolts and nuts Ill. The cylinder liners and the head have the usual passages l2 for the circulation of cooling water. A gasket H is placed between the liners and the, head 8.

The head 8 over each cylinder has four exhaust openings l6 delivering into an exhaust chamber 18, from where the exhaust gases pass through a passage to the exhaust manifold. Each opening has a valve 20, the stem of which projects upwardly through a bearing 22 in the head 3. Only two openings l6 and two valves 20 are shown, the other two being structural duplicates 01' those shown.

hydraulic lash adjusters.

The stem of each valve 20 has a ribbed end to receive the haltkeys 24, held on the stem by the spring retainer 26. Springs 28 are confined under compression between the retainers 26 and the head 8 and always urge the valves .to the closed position as shown in Figure 1. 0n the end of eachvalve stem a cap 30 is positioned.

The head has a recess 3| between each pair of valves and the top or this recess is formed into a spherical seat 32 in which there is received the spherical lower end of the bearing head 34. The bearing head 34 has a bore in which there slides the shank 33 of a T-shaped bridge 38. A compressed coil spring 38' is positioned between the bridge 38 and a flange on the head 34. The bridge extends over the ends of the valve stems and is provided on its underside with recesses 31 and 39. In each recess a hydraulic lash adjuster unit 40 is secured. Each a ball 52 which is adapted under certain conditions to close the passage 48. A passage 85 in the fixture connects the recess with the interior of the piston and a compressed coil spring 56 is positioned between a shoulder on the fixture 50 and the piston 44. A space 58 is allowed between the recesses 37 or 39 and the shell 42, and this space is connected by a passage 60 with an opening 82. The opening 62 is connected by an opening 84 in a bearing plug 63 positioned in a. recess in the top of the bridge 38. This plug has a spherical upper surface to receive the ball end 68 secured to the end of the rocker arm 10. A passage (not shown) in the rocker arm leads from a source of lubricant to cause oil pressure to be exerted in the lash adjuster units 40 through the openings 64 and 62.

The rocker arm 10 is mounted on a rocker arm shaft 12, and a camshaft ll operateson a roller 16 on the rocker arm to operate the arm.

The unit structed slightly difl'erent from the unit I. on the'right. The left hand unit is screw threaded into the recess 39 as is shown at 13 and the lower flange is broader. On the underside of the flange 30 radial recesses 32 are applied.

40 on the left (Figure 3) is con- A relatively flat spring 84 is applied to the bridge 3! at a shoulder where the shank ll joins to the head of the bridge. The spring 84 is urged against the shoulder by the spring ll. The spring 84 is provided with an opening in which the shank II flts closely. The spring has a finger ll bent therefrom and received-in a recess I! in the bridge. The finger 88 and recess '8 are to prevent the spring from turning. The spring is upwardly bent at 89 and the end is forked and the fork straddles the left side piston 44 (Figure 2). Each tine of the fork is provided with a protuberance 90 which is adapted to engage in one of the recesses 82 to hold the unit 40 in adjusted position.

The adjustment of the valves at the two sides of the bridge is accomplished as follows: The stem 82 of the ball end 88 is screw threaded into the end of the rocker arm I and a lock nut 94 holds the threaded stem 92 in position. The bridge 38 as a whole can be adjusted by loosening the nut 94 and turning the stem 92 to cause the bridge 88 to move up or down. In this way an adjustment can be accomplished for the right hand valve in Figure 2. A gage is now placed between the cap 30 on the left and the flange 80 of the hydraulic unit and should the interposition of the gage cause either valve to open slightly, then the unit 40 on the left is turned on its threaded connection to move the unit farther into the recess 30 until both valves are in closed position. Should the space between the flange II and the cap it be greater than the thickness of the gage, then the unit 40 is unscrewed to move it closer to the cap. The protuberances I will engage in the grooves 82 to hold the unit in adjusted position.

The adjustment just described enables the elimination of shims which formerly were used and which were placed between the end of the valve stem and the cap.

I claim:

1. In a valve operating mechanism for an internal combustion engine having a plurality of engine valves held seated by spring means, a rocker arm for operating said valves, a valve bridgesrrangedtcbeactuatedbysaidarmengaging the bridge at a point between said valves, oil pressure passages in said bridge and a hydraulic lash adjuster unit in said bridge adjacent each valve, each unit comprising a hollow body having a recess and a fluid inlet passage therein communicating with one of said pressure passages in the bridge, an inlet check valve in the recess adjacent the inlet passage, check valve retaining means in said recess, a hollow piston slidable in the body and a sprin between said piston and said retaining means. the last mentioned spring being guided by the inner wall of said piston, so that each piston is urged into contact with an adjacent engine valve by the fluid and spring pressure within the valve body, one of said units being firmly secured in the bridge and the other being adjustably secured therein for adjustment relative to the adjacent engine valve.

2. In a valve operating mechanism for an internal combustion engine having a plurality of engine valves held seated by spring means, a rocker arm for operating said valves, a valve bridge arranged to be actuated by said arm engaging the bridge at a point between said valves, oil pressure passages in said bridge, a hydraulic lash adjuster unit in said bridge adjacent each valve, each unit comprising a hollow body having a recess and a fluid inlet passage therein communicating with one of said pressure as in the bridge, an inlet check valve in the recess adjacent the inlet passage, check valve retaining means in said recess, a hollow piston slidable in the body and a spring between said piston and said retaining means, the last mentioned spring being guided by the inner wall of said piston, so that each piston is urged into contact with an adjacent engine valve by the fluid and spring pressure within the valve body, one of said units being firmly secured in the bridge and the other being threaded therein for adjustment relative to the adjacent engine valve, and resilient locking means be-- tween the bridge and the adjustable unit for locking it in adjusted position.

EUGENE W. KETTERING. 

